Commutator for electrical machines.



I s. VON AMM-ON. OOMMUTATOR FOR ELECTRICAL MACHINES.

APPLICATION FILED APB..10, 1908.

Patented Feb. 27, 1912.

i=7 E L WITNESSES:

AT'TORNEY COLUMBIA PLANOORAPH CUnWASH lNflTON, D. C

UNITED STATES PATENT oEEIoE.

SIEGFRIED VON AMMON, 0F BOWDON, ENGLAND, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, OF EAST PITTS- BURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

COMMUTATOR FOR ELECTRICAL MACHINES.

To all whom it may concern Be it known that I, SIEGFRIED VON AM- MON, a subject of the Kingdom of Prussia, and a resident of Bowdon, in the county of Chester, England, have invented a new and useful Improvement in Commutators for Electrical Machines, of which the following is a specification.

My invention relates to commutators for electrical machines and in particular to commutators, the segments of which are held in position by shrink rings or other bands passing around their exterior surfaces. In this type of commutator, short-circuiting of the segments by the shrink rings must necessarily be prevented by interposing insulating material between the shrink rings and the segments, but difliculty has heretofore been experienced in insulating the lateral or plane surfaces of the rings in order to prevent arcs occurring between the segments and the rings or between the brushes and the rings. This difficulty is greatly increased in the case of grooved commutators intended to be run at a high speed, in which case, the peripheral speed of the shrink rings is very high.

According to my present invention. in order to overcome the difficulties above mentioned, I insulate the shrink rings or hands by means of annular plates or shields of insulating material of any suitable form, which do not rotate with the commutator but are supported from a fixed part of the machine at a suitable distance from the surfaces of the shrink rings which it is desired to guard.

The invention is illustrated in the single figure of the accompanying drawings which is a sectional view of one half of a commutator embodying the invention.

Referring now to the figure, the shaft 1 of the electrical machine is provided with conical bushings 3 which support a commutator comprising a plurality of insulated segments 2, insulating rings 4 being interposed between the segments 2 and the bushings 3. The segments 2 are held together by means of shrink rings 5 and 6 located at the respective ends of the segments 2 and by a central shrink ring 7, insulating rings 8 being provided to prevent the commutator segments from being short-circuited by the shrink rings.

Specification of Letters Patent.

Application filed April 10, 1908.

Patented Feb. 27, 1912.

Serial No. 426,364.

As illustrated in the drawing, the commutator is of the grooved type, being provided with brushes 9 that are adapted to make cont-act with the radial faces of the commutator grooves. The brushes 9 are carried by brush holders 10 which are supported from brush rings 12 by a brush arm 11. In order to prevent arcs-occurring between the segments 2 or between the brushes 9 and the shrink rings 5, 6, and 7, stationary annular plates or shields 13 of insulating material are provided which are attached to the brush arm 11 and to the brush rings 12, as shown, but which may be supported in any other suitable manner. The inner edges of the annular plates 13 are located in grooves 14 in the commutator segments 2 and may be of any suitable hard insulating material, such, for example, as vulcanized fiber or micanite. 1

It will be understood that, if desired, the inner edges of the shields 13 and the portions of the commutator segments which are engaged thereby may be modified as to form from what is shown, if desired.

Other modifications from the precise arrangements herein shown and described may evidently be made without departing from the spirit and scope of the invention.

I claim as my invention:

1. A commutator for dynamo-electric machines comprising segments or bars, a plurality of clamping rings surrounding said segments or bars and insulated therefrom and stationary annular plates or shields of insulating material located adjacent to the said rings, for the purpose specified.

2. A commutator for a dynamo-electric machine provided with stationary annular insulating plates or shields located between commutator brushes and disposed in planes perpendicular to the commutator cylinder ax1s.

3. In a dynamo-electric machine, the combination with a commutator cylinder and brushes in engagement therewith, of stationary annular insulating barriers bet-ween the brushes.

4. In a dynamo-electric machine, the combination with a commutator cylinder and brushes in engagement therewith, of a pair of stationary annular insulating barriers between adjacent sets of brushes.

5. In a dynamo-electric machine, the combination with a commutator cylinder having a plurality of insulated segments, and brushes in engagement with the commutator cylinder surface, of annular barriers of insulating material disposed between the brushes and stationary relative to the commutator cylinder.

6. In a dynamo-electric machine, the combination with a commutator cylinder comprising a plurality of insulated segments and bands or shrink rings for holding the segments in position, of stationary brushes that engage the surface of the commutator cylinder between the rings, and stationary insulating barriers between the rings and the brushes.

7. In a dynamo-electric machine, the combination with a commutator cylinder comprising a plurality of insulated segments and metal bands or shrink rings for holding the segments in position, said bands or rings being insulated from the segments, of stationary supporting rods substantially parallel to the axis of the commutator, brushes engaging the commutator cylinder, brush supporting arms secured to the stationary rods, and annular barriers of insulating material secured to the stationary rods and located between the brushes and the metal bands or rings.

8. In a dynamo-electric machine, the combination with a commutator cylinder having a plurality of annular recesses, and stationary brushes engaging the walls of said recesses, of stationary insulating barriers be- 1 tween the recesses, the inner edges of which are adjacent to the commutator cylinder.

9. In a dynamo-electric machine, the combination witha commutator cylinder comprising a plurality of insulated segments and having annular recesses, of bands or shrink rings for holding the segments in position, stationary brushes that engage the walls of the recess s, and stationary annular insulating barriers between the brushes and the rings, the inner edges of which are ad jacent to the commutator cylinder.

10. In a dynamo electric machine, the combination with a commutator cylinder comprising a plurality of insulated segments and having annular recesses, metal bands or shrink rings for holding the segments in position, said bands or rings being insulated from the segments, of stationary supporting rods substantially parallel to the axis of the commutator, brushes engaging the walls of the annular recesses, brush-supporting arms secured to the stationary rods, and annular barriers of insulating material also secured to the rods and having their inner edges located adjacent to the commutator cylinder and between the arms and the metal bands or rings.

In testimony whereof, I have hereunto subscribed my name this seventeenth day of March, 1908.

SIEGFRIED VON AMMON. lVitnesses:

NORMAN H. SHEARD, Jas. STEWART BROADFOOT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

